Just plain wear will do it in time. My 1971 was a very rough action when new. Now, it's almost as good as my pre-64's. It will never be an 1886, or a 1892 for that matter, but, a 94 can be very smooth in time. Try just sitting and cranking it a thousand times. then clean and oil. It makes a notable difference in a new '94.
The experts will disassemble a rifle, and polish the wear areas to a mirror finish.
the 94 isn't terribly difficult to disassemble, if you have mechanical aptitude, and a good diagram.
But, a few on this very site (no names here) have had assistance from the guys here when they tried it, and needed all the kings men.